[llvm] [profcheck] Add unknown branch weights to expanded cmpxchg loop. (PR #165841)

[Jin Huang via llvm-commits]

jinhuang1102 wrote:

> > Thanks for letting me know! Yes, I will remove all of these expected failed tests after the PR is merged!
> 
> Is there a reason you can't update it as part of this PR?

Because not all 45 failed tests are fixed in this single PR. I will update them after all PR merged.

https://github.com/llvm/llvm-project/pull/165841